Investigation and monitoring of slope instabilities in a rupestrian-heritage area (Basilicata, south Italy).

In this paper are reported the geological and geomorphologic studies and the main results of the monitoring survey carried out on near the city of Matera in Basilicata region (southern It-aly). The “Sassi di Matera” are, since 1993, UNESCO World Heritage. In particular this work has been done in an area, the “Parco Archeologico Storico Naturale delle Chiese Rupestri del Materano", where fine rupestrian heritages are present. In this area, the considerable acclivity of the slopes and the lithological defects and intense fracturing state of carbonate rocks cause mass movements of the blocks in terms of rock falls, topples and rockslides. The potentially unstable carbonate blocks have been defined by geological and geomorphologic surveys with particular attention to the influence of the state of fractures of the blocks. Some specific sur-veys have been carry out and the data have been analyzed following the method of Mathe-son, (1983, 1989) to obtain information about the principal directions of fracture sets and to define an index of relative risk. Detailed analyses have been carried out in the test sites showed in figure 1 and the potentially unstable carbonate blocks that need survey have been defined. On the basis of these results a landslide monitoring activities it’s started and it’s still going on. The survey is made up by traditional survey system and new technologies: a tradi-tional topographic survey, GPS measures and a deformation measurement system. The adoption of a "mixed" approach, with the contemporary use of classical techniques and GPS and ground deformation measurement could allow the capability of combination/validation behind the data coming from each measurement system and could gives a more reliable in-formation about eventual mass movements of blocks.